Phosphonous and thiophosphonous acid esters

ABSTRACT

Compounds useful as stabilisers for organic materials of the formula   WHEREIN X is -CH2-, -O- or -S-, Y1 and Y2 are -O- or -S-, R1 and R2 are hydrocarbon radicals, and RINGS A and B may be substituted by alkyl groups, and inorganic salts of compounds in which either of R1 and R2 is hydrogen.

United States Patent 1 91 Hofer et al. Sept. 2, 1975 4] PHOSPHONOUS ANDTHIOPHOSPHONOUS 3,071,609 1/1963 Campbell et a1 260/962 x ACID ESTERS3,264,324 8/1966 Gould et al. 260/962 x Inventors: Kurt Hofer,Munchenstein;

Guenther Tscheulin, Riehen, both of Switzerland Assignee: Sandoz Ltd.,Basel, Switzerland Filed: Mar. 28, 1974 Appl. No.: 455,597

Related US. Application Data Continuation-impart of Scr. No. 308,594,Nov. 21, 1972, Pat. No. 3,875,264.

Foreign Application Priority Data Novv 24, 1971 Switzerland 17129/71 US.Cl 260/951; 260/45.7 PS; 260/45.7 P; 260/429 R; 260/429.9; 260/438.1;

260/439 R; 260/448 R; 260/502.4 R; 2611/5024 P; 260/932; 260/949;260/962 Int. C1. C07F 9/48 Field of Search 260/949, 951, 962

References Cited UNITED STATES PATENTS 12/1951 Morris ct al. 260/951 X9/1959 Harowitz 260/962 X Primary Examiner-Richard L. Raymond Attorney,Agent, or Firm-Gerald D. Sharkin; Richard E. Vila; Joseph J. Borovian[57 ABSTRACT Compounds useful as stabilisers for organic materials ofthe formula 14 Claims, No Drawings PHOSPHONOUS AND THIOPHOSPHONOUS ACIDESTERS This application is a continuation-in-part of our copending US.application Ser. No. 308,594, filed on Nov. 21, 1972 now US. Pat. No.3,875,264.

The present invention relates to phosphonous acid derivatives.

More particularly, this invention provides compounds of formula I,

in which n signifies or 1,

Y Y Y and Y,, which may be the the same or different, each signifies Oor S,

R,, R R and R which may be the the same or different, each signifies ahydrocarbon radical of up to carbon atoms consisting of aromatic and/orsaturated aliphatic units,

and

rings A and B may be either further unsubstituted or each furthersubstituted by 1 or 2 alkyl groups of 1 to 6 carbon atoms, and inorganicsalts of compounds in which any of R to to R is hydrogen.

X preferably signifies O and n preferably signifies 1. Y Y Y and Y arepreferably the same, and R,, R R and R are preferably also the same. Inthe preferred compounds, the

substituent or each substituent is in the para position of the nucleus.

Suitable hydrocarbon radicals for R R R and R include the following:alkyl radicals, preferably other than tertiary alkyl radicals,, of up to20, preferably up to 12, in particular 1 to 6 carbon atoms, for examplen-alkyl radicals such as methyl, ethyl, propyl, butyl, pentyl, hexyl,hcptyl, octyl, nonyl, decyl, undecycl and dodecyl, secondary alkylradicals such as isopropyl, 2- butyl, 3-methyl-2-butyl, Z-pentyl,2,2-dimethyl-3-butyl,

Z-hexyl, 3-hexyl, 2-mcthyl-3-pheny1, 3-methyl'2- pentyl,4-methyl-2-pentyl, 2,2-dimethyl-3-pentyl, 2,4-dimethyl-3pcntyl,Z-heptyl, 3-heptyl, 4-heptyl,

2 decyl, 7-ethyl-2-methyl-4-nonyl, 2-dodecyl, 2,6,8- trimethyl-4nonylZ-tridecyl Z-tetradecyl, 2-

pentadecyl, 2-hexadecyl, 2-nonadeey], alkyl radicals bound through aprimary carbon atom but otherwise branched, for example2-methyl-1-propyl, 2,2-dimethyl-l-propyl, 2-methyl-l-butyl,Z-ethyl-l-butyl, 2,2- dimethyll -butyl, 2methy1-1-pentyl, 3-methyl- 1pentyl, 4-methyl-1-pentyl, 2,4-dimethyl-l-pentyl, 2- ethyl- 1 -hexyl,2,2-dimethyll -hexyl, 2,2,4-trimethyll pentyl, 4-methyl-2-propyll-pentyl, 3,7-dimethyl- 1 octyl, 2,2-dimethyl-1-decyl; cycloalkylradicals of up to 20, preferably 3 to 12, in particular 5 to 8 carbonatoms, optionally substituted by l, 2 or 3 alkyl radicals, for exampleof 1 to 4 carbon atoms, such as cyclopentyl, cyclohexyl, cycloheptyl,2-, 3- or 4-methylcyclohexyl, cyclooctyl, 2,5-, 2,6-, 3,4- or3,5-dimethylcyclohexyl, l-cyclohexyl-propyl, 2-propylcyclohexyl,3,3,S-trimethylcyclohexyl, 2-butylcyclohexyl, 4-tert- .butylcyclohexyl,3-methyl-6-iso-propylcyclohexyl, cyclododecyl, l-methylcyclopentyl,l-methylcyclohexyl, l-methylcycloheptyl, 1 -propylcyclopentyl,l-butylcyclopentyl, l-butylcyclohexyl and l-pentylcyclopentyl;cycloalkylalkyl radicals, in particular C cycloalkyl C alkyl radicals,for example cyclohexyl-methyl, 2- cyclohexyl-ethyl, cycloheptylmethyl,3- cyclohexylpropyl, cyelooctylmethyl, cycloundecylmethyl andcyclododecylmethyl; aryl radicals, for example phenyl or diphenyl,optionally substituted by l, 2 or 3 alkyl radicals, e.g. of l to 12,preferably 1 to 6 carbon atoms, such as those alkyl radicals mentionedabove and also tertiary alkyl radicals, such as tert.butyl,2-methyl-2-butyl, 2,3-dimethyl-2-butyl, 2-methyl-2- pentyl,3-methyl-3pentyl, 3-ethyl-3-pentyl, 2,4 dimethyl-2-pentyl,2-methyl-2-hexyl, 3-methyl-3- hexyl, 3,4-dimethyl-3'hexyl,3,5dimethyl-3-hexyl,

2-methyl-2-heptyl, 3methyl 3-heptyl, 4-methyl-4- heptyl,2,3,4-trimethyl-3pentyl, 2,4,4-trimethyl-2- pentyl, 3-ethyI-3-heptyl,2-methyl'2-octyl, 4-methyl-4 octyl, 3,6-dimethyl-3-octyl,3,7-dimethyI-3-octyl, 4,4, 4,6,6-pentamethyl-2heptyl, as well as l-alkylsubstituted cycloalkyl radicals, such as those mentioned above; examplesof such substituted ary] radicals include 2-, 3- and 4-methylphenyl,2,3-, 2,4-, 2,5-, 3,4- and 3,5-dimethylphenyl, 2-, 3- and 4-ethylphenyl,2,3,5- and 2,4,5-trimethylphenyl, 3-ethyl-5- methylphcnyl,4-sec.butyl-phenyl, 2- and 4- tert.butylphenyl,5-isopr0py1-2-methy1phenyl, 2-isopropyl-5- methylphenyl,3-isopropyl-5-methy1phenyl, 4-tert.pentylphenyl,2tert.butyl4-methylphenyl, 4-tert.butyl-2- mcthylphenyl,6-tert.butyl-3-methylphenyl, 2,4-ditert.butylphenyl, 4( l ,1',3',3-tetramethylbutyl)- phenyl, 2-methyl-4( l ,1,3' '3'-tetramethylbutyl phenyl, 4-nonylphenyl (mixture of isomers), and2,4-di-tert.octyl-phenyl; aralkyl radicals, such as phenyl or diphenylalkyl radicals, the alkyl radicals of which suitably contain 1 to 12,particularly 1 to 6 carbon atoms, and the aryl radicals of which mayoption ally be alkyl substituted as above, including benzyl, landZ-phenyl-ethyl, l-phenyl-l-propyl, l-phenyl2- propyl, 2pheny1*1-propyl,3-phenyl1'propyl, 1(otoly1)-ethyl, l-(m-tolyl)-ethyl, l-(p-toly1)-ethyl,1- phenyll -butyl 2-( 2',4',6'-trimcthylphenyl )-ethyl, l-phcnyll-pentyl, l-( 4-tert.buty1phcnyl )-ethyl, 4-methy1-l-phenyl-2-pcntyl andbenzohydryl. The preferred hydrocarbon radicals for R,, R R and R include alkyl radicals, other than tertiary alkyl radicals. of l to 12, inparticular 4 to 12 carbon atoms, such as n-butyl or n-dodecyl, andphenyl and diphenyl radicals, optionally substituted by I or 2 alkylradicals of I to 4 carbon atoms, preferably tertiary such alkylradicals, such as 2,4-di-t-butylphenyl, 2-t-butyl-diphenyl, and2,4-di-tbutyldiphenyl.

The rings A and B may, as indicated, be substituted by l or 2 alkylgroups of up to 6, preferably up to 4 carbon atoms, for example suchalkyl groups as mentioned above, but are preferably unsubstituted.

The invention also provides a process for the production of compounds offormula I and inorganic salts thereof, characterised by reacting acompound of formula II,

Hal 1 P P Hal w g in which X, n and rings A and B are as defined above,

and

the radicals Hal, which may be the same or different,

each signify a halogen atom, with compounds of formula III and IV,

HYIR, m

in which R R Y and Y are as defined above, and, if n signifies l, withcompounds of formula V and VI,

H a ZI V in which R;,, R Y and Y are as defined above, and, whererequired, converting the resulting product into an inorganic salt. Aswill be appreciated, two or more of the compounds III, IV, V and VI maybe the same, in which case the molar quantity of the compound isadjusted accordingly.

The process of the invention may suitably be carried out in conventionalmanner, for example as described by K. Sasse, Houben-Weyl (eds.),Methoden der organischen Chemie, 4th impression (1963), Vol. XII/l, pp.3l8/ff. As will also be appreciated, however, the particular conditionsemployed depend, to an extent, on the particular compounds III, IV, V orVI being employed. For example, in some instances, it may be advisableto apply external cooling to the reaction mixture to restrain thevigorous reaction. Thus, for example, when any of the compounds III, IV,V and VI is water, then it is preferable to charge the reaction mixturewith an excess of water and to add the compound II with cooling andstirring and at a rate slow enough to ensure that the exothermicreaction does not lead to an Hal Hal

unduly high temperature. Where the compounds III,

IV, V or VI are alcohols or phenols, the reaction may suitable becarried out at a temperature of from to C, in the presence of an acidbinding agent such as pyridine or a trialkylamine.

Where the compound II is reacted with water, products are formedcontaining radicals of formula Vlla and VIII) VIIa kaline earth metal,e.g. calcium or magnesium, zinc,

manganese, aluminium, copper, vanadium, cobalt and nickel salts. Thesalts may be produced by reaction of the free acid with an inorganichydroxide or salt, such as calcium hydroxide, zinc oxide, sodiumcarbonate, potassium bicarbonate, aluminium acetate, borium chloride,nickel acetate and zinc chloride.

Preferably, however, the reaction of the compounds II with water andproduction of salts is carried out in a single operation. For thispurpose, an' excess of water may be provided for hydrolysis of thecompound II, and after addition of the appropriate inorganic reagent,the compound II may be slowly added, with stirring, as indicated above.

The resulting compounds of formula I and inorganic salts thereof may beisolated and purified using conventional techniques.

The compounds of formula II, employed as starting materials are eitherknown or may be produced in conventional manner from availablematerials, for example as described by K. Sasse, Houben-VVehl (eds),Methoden der organischen Chemie, 4th impression (1963), Vol. XII/l,organische Phosphorverbindungcn, Part I, pp. 302-318. Thus, for example,the compound Ila,

is described in Journal of the Chemical Society, I932, 2880. In general,compounds of formula II may be produced by reacting the appropriatediphenylmethane, oxide or sulphide, with a phosphorus trihalide,preferably phosphorus.trichloride. The process may suitably be effectedat an. elevated temperature in the gaseous phase,,although it is morepreferable to react under milder conditions in the presence of acatalyst, e.g. a

FriedelKrafts catalyst, in particular aluminium trichloride. It ispreferable to .work with phosphorus trichloride at its boilingtemperature. After reaction, any aluminium chloride complex of thecompound Il may be decomposed, for example with phosphorus oxychlorideor pyridine.

The resulting compounds of formula Il may be iso lated and purifiedusing conventional techniques.

The compounds of the invention are useful as stabilisers for organicmaterials which are sensitive to light, oxygen and heat. For thispurpose, they may be ineorporated in or applied to form a protectivesurface film on the organic material. When thus applied, the newcompounds by their stabilizing action protect sensitive materialsagainst degradation. They have a wide area of use in the processing ofplastics materials, being suitable, for example, as stabilizers forcellulose acetate, cellulose acetobutyrate, polyethylene, polypropylene,polyvinyl chloride, polyvinyl chloride acetate, polyamides, polystyrene,ethyl cellulose, cellulose nitrate, polyvinyl alcohol, silicon rubber,cellulose propionate, melamine-formaldehyde resins, urea-formaldehyderesins, allyl casting resins, polymethyl methacrylate, polyesters,polyacrylonitrile, and eopolymers of these polymers. The compounds mayalso be used for the stabilization of natural products such as rubber,cellulose, wool and silk.

The materials for stabilization may suitably be in the form of film orsheet, rods, coatings, panels, tapes, fibres, granules, powders or otherprocessing forms, or as solutions, emulsions or dispersions. Thestabilizing compounds may be incorporated in or coated on the materialsby conventional methods. An important method of application consists inintimately mixing polymeric material, for example polypropylenegranules, with the stabilizer in a kneader or other suitable machine,followed by extrusion. This method ensures homogeneous distributionwhich is important for good protection. The material can be extruded,for example, as film, tubing or filament, the latter for conversion intotextiles. In this method of application, the stabilizer may beincorporated in, for example, the polypropylene prior to textileproduction. The new stabilizers, however, can also be applied to textileyarns and fabrics from an aqueous medium containing a finely dispersedcompound of formula (I). This method is partic ularly suitable for, e.g.textiles of polyethylene terephthalate and cellulose acetate fibres.

Synthetic polymeric materials need not necessarily be in the final formbefore incorporation of the compounds of the invention. Thus, thesecompounds may a plastics, fluorescent pigments, automobile and furniturepolishes, creams. lotions and related products, which may be opaque.clear or translucent.

As regards the constitution of compounds of formula I and their action,it may be mentioned that particularly good stabilization is obtained inpolyalkylenes, notably polypropylene, when the molecule of the compoundof the invention consists to a large extent of saturated aliphaticgroups. When phosphonous acids of formula I in which R R R and Rrepresent hydrogen are employed in the form of the nickel salts, thestabilizing action against visible light and ultra-violet radiation isparticularly effective, especially in polyalkylenes. The manganese andcopper salts are particularly suitable for stabilizing polyar nidesagainst degradation by ultraviolet radiation, while the salts of othertransition metals such as vanadium and cobalt, are suitable asultraviolet absorbers in a number of substrates.

The present invention also comprises the sensitive organic materialscontaining a compound of formula I for stabilization. As previouslyindicated, the new compounds can be incorporated in the organicmaterials at any stage of processing using standard methods. The amountsof stabilizer employed may vary within wide limits, for example from0.01 to 5 percent or preferably from 0.05 to 1 percent in relation tothe weight of the material. The stabilized organic materials may containcompounds of formula I alone, or together with further additives, forexample ultra-violet absorbers and other stabilizers against degradationby heat and oxygen. As regards the latter, suitable stabilizers arethose belonging to different chemical classes to the compounds offormula I, for example organic compounds of sulphur, tin and pentavalentphosphorus, sterically hindered phenols, 2-hydroxy-benzophenones andhydroxybenzotriazoles. Often, notably high stabilization may be obtainedwith such mixtures since they may have a synergistic action.

In the following Examples the parts and percentage are by weight and thetemperatures in degrees centigrade.

EXAMPLE A Production of an Intermediate of Formula II c1 \Cl is obtainedin the form of a pale red oil with a pungent odour.

IIC

EXAMPLE l In the absence of moisture, a solution of 20 parts of thediphenylether diehlorophosphine of formula Ila, above, in 50 parts oftoluene is added at ()5 to 29.9 parts of dodecyl mercaptan and 15 partsof triethylamine in parts of toluene. The solution is allowed to reactovernight at 40. Subsequently, the precipitated salt is filtered, thefiltrate evaporated under vacuum, and the residue crystallized fromabsolute ether. m.p. 2526 Elementary analysis C H P C H OPS found 71.49.9 5.6 calculated 71.6 9.8 5.2

EXAMPLE 2 At 5, a solution of 33.4 parts of the diphenyletherdichloro-phosphine of formula Ila, above, in 50 parts of toluene isadded to 50.7 parts of 2,4-di.-tert.butylphenol and parts oftriethylamine in 200 parts of toluene in the absence of moisture. Thesolution is allowed to react overnight at the precipitated productfiltered, the filtrate evaporated under vacuum, and the residuecrystallized from ether/methanol. m.p. 8889.

Elementary analysis P w m a found 5.4

calculated 5.]

EXAMPLE 3 A solution of 95.5 parts of4,4'-diphenylether(bisdichloro-phosphine of formula Ile, above, in 50parts of toluene is added, at O5, in the absence of moisture, to 21 1parts of 2,4-ditert.butylphenol and 104 parts of triethylamine in 300parts of toluene. The solution is allowed to react overnight at 40, theprecipitated product filtered, the filtrate evaporated under vacuum, andthe residue triturated with methanol and crystallized from benzene. m.p.77-80.

Elementary analysis H P EXAMPLE 4 EXAMPLE 5 A solution of parts of4,4-diphenylether(bischlorophosphine) in parts of toluene is added, atO5, to 136.3 parts of 2,4'-di-tert.butyl-4-phenyl phenol and 49 parts oftriethylamine in 300 parts of toluene, in the absence of moisture. Thesolution is allowed to react overnight at 40, the precipitated saltfiltered, the filtrate evaporated under vacuum, and the residuetriturated to a white powder. m.p. 8285.

EXAMPLE 6 A solution of 12.5 parts of4,4'-diphenylether-(bisdichlorophosphine) in 50 parts of toluene isadded at -5 to 9.9 parts of butanol and 14 parts of triethylamine inparts of toluene in the absence of moisture. The solution is allowed toreact overnight at 40, the precipitated salt filtered and the filtrateevaporated under vacuum to yield a pale yellow oil.

CWHMOSPL, found 77.2 8A 5) 30 The structural formulae of the compoundsproduced calculated 77.6 8.8 5.9 in Examples 1 to 6 are shown in Table lbelow.

Table 1 Example O P/ No.

Significance of Q I n l C H S- O 2 (tert. 11 C Q 0 (tert. H 4

3 do. 4 O l (tert H C 4 Tablel -Continued Exam le 1 L O .P No.

Significance of Q n I (tert )H9C4 1 (tert. H C

6 H9C4-O l [n analogous manner to that described in Example 1, in whichX signifies CH or the compound of the formula:

o ao

C(CH

-C (CH is produced.

USE EXAMPLE A. Stabilisation against heat discolouration When workingwith polypropylene incorporating 0.2 percent of the stabiliser2,2-Methylen-bis-(4-methyl- 6-tert.butylphenol) at a temperature ofabout 220, 21 brownish colouration occurs. This can be minimised byincorporation into the polypropylene of 0.1 percent of a compoundaccording to any one of Examples 1 to 6.

B. Stabilisation against oxidative degradation Polypropylene, whichcontains, as antioxidant, 0.2 percent of4,4-Methylen-bis-(2,6-di-tert.butylphenol) is intimately mixed with 0.1percent of a compound produced in any one of Examples 1 to 6. Theplastic is stored, in the form of thin discs, under oxygen in a closedsystem after removal of air. The system is then warmed to 190, wherebyan excess pressure of about Y, and Y which may be the same or different,each signifies O or S,

R and R which may be the same or different, each signifies a hydrocarbonradical of up to 20 carbon atoms selected from the group consisting ofalkyl; cycloalkyl which may be substituted by up to 3 alkyl groups;cycloalkylalkyl; phenyl which may be substituted by up to 3 alkyl oralkylcycloalkyl groups; dipehnyl which may be substituted by up to 3alkyl or alkylcycloalkyl groups; and phenyl and diphenylalkyl, the arylportions of which may be substituted by up to 3 alkyl groups,

and rings A and B may be either further unsubstituted or furthersubstituted by l or 2 alkyl groups of l to 6 carbon atoms.

2. A compound of claim 1, in which X signifies 3. "A compound of claim1, in which Y and Y are the same.

4. A compound of claim 1, in which R and R are the same.

5. A compound of claim 1, in which the P substituent is in the paraposition of the nucleus.

6. A compound of claim 1, in which rings A and B are each furtherunsubstituted.

7. A compound of claim 1, in which R and R each signifies an alkylradical of l to 12 carbon atoms, a cycloalkyl radical of 3 to 12 carbonatoms, which may be substituted by l, 2 or 3 alkyl groups of 1 to 4carbon atoms, a cycloalkylalkyl radical in which the cycloalkyl portioncontains 5 to 12 carbon atoms and the alkyl portion 1 to 6 carbon atoms,or a phenyl or diphenyl radical which may be substituted by l, 2 or 3alkyl radicals of l to 12 carbon atoms.

8. A compound of claim 1, in which R, and R each signifies an alkylradical of l to 6 carbon atoms, a cyeloalkyl radical of 5 to 8 carbonatoms, which may be substituted by l, 2 or 3 alkyl groups of l to 4carbon atoms, a cycloalkylalkyl radical in which the cycloalkyl portioncontains to 8 carbon atoms and the alkyl portion contains 1 to 4 carbonatoms, or a phenyl or diphenyl radical which may be substituted by 1, 2or 3 alkyl radicals of l to 6 carbon atoms.

9. A compound of claim 1, in which R and R each signifies an alkylradical of 4 to 12 carbon atoms, or,

14. The compound of claim '1, of the formula ye H

1. A COMPOUND OF FORMULA
 2. A compound of claim 1, in which X signifies-O-.
 3. A compound of claim 1, in which Y1 and Y2 are the same.
 4. Acompound of claim 1, in which R1 and R2 are the same.
 5. A compound ofclaim 1, in which the P substituent is in the para position of thenucleus.
 6. A compound of claim 1, in which rings A and B are eachfurther unsubstituted.
 7. A compound of claim 1, in which R1 and R2 eachsignifies an alkyl radical of 1 to 12 carbon atoms, a cycloalkyl radicalof 3 to 12 carbon atoms, which may be substituted by 1, 2 or 3 alkylgroups of 1 to 4 carbon atoms, a cycloalkylalkyl radical in which thecycloalkyl portion contains 5 to 12 carbon atoms and the alkyl portion 1to 6 carbon atoms, or a phenyl or diphenyl radical which may besubstituted by 1, 2 or 3 alkyl radicals of 1 to 12 carbon atoms.
 8. Acompound of claim 1, in which R1 and R2 each signifies an alkyl radicalof 1 to 6 carbon atoms, a cycloalkyl radical of 5 to 8 carbon atoms,which may be substituted by 1, 2 or 3 alkyl groups of 1 to 4 carbonatoms, a cycloalkylalkyl radical in which the cycloalkyl portioncontains 5 to 8 carbon atoms and the alkyl portion contains 1 to 4carbon atoms, or a phenyl or diphenyl radical which may be substitutedby 1, 2 or 3 alkyl radicals of 1 to 6 carbon atoms.
 9. A compound ofclaim 1, in which R1 and R2 each signifies an alkyl radical of 4 to 12carbon atoms, or phenyl or diphenyl radical, which may be substituted by1 or 2 alkyl radicals of 1 to 4 carbon atoms.
 10. A compound of claim 1,in which R1 and R2 each signifies other than a tertiary alkyl radical.11. A compound of claim 1, in which R1 and R2 each signifies n-butyl,n-dodecyl, 2,4-di-t-butyl-phenyl, 2-t-butylphenyl, or2,4-di-t-butyldiphenyl.
 12. A compound of claim 1, wherein X is oxygen,Y1 and Y2 are each oxygen and R1 and R2 are each alkyl of 1 to 8 carbonatoms.
 13. The compound of claim 1, of the formula:
 14. The compound ofclaim 1, of the formula